The present invention relates to an ozone supplying apparatus. More particularly, it relates to an ozone supplying apparatus for producing and storing ozone by using electricity which is capable of supplying stored ozone continuously or intermittently at specified ratios to an ozone consuming object.
There has been conventionally known an intermittent type ozone supplying apparatus for temporarily storing ozone which comprises the following components as shown in FIG. 15: an ozone generator 50, an oxygen supply source 51, a circulating blower 52, an adsorption/desorption tower 53 for temporarily storing generated ozone, a cooling source 54 for cooling the adsorption/desorption tower 53, a heating source 55 for heating the adsorption/desorption tower 53, a water flow ejector 56 for taking ozone out from the adsorption/desorption tower 53 through decompression and suction, and a group of switch valves 57a to 57g. The adsorption/desorption tower 53 is of double cylinder type as shown in FIG. 16, wherein an inner cylinder 58 is filled with an ozone adsorbent 59 and is further provided with a spiral heat transferring pipe 60 for heating (refer to Japanese Examined Patent Publication No. 64484/1985). A cooling piping 61 through which a cooling medium is made to flow is wound around an outer surface of the inner cylinder 58 in a spiral manner. On the other hand, an outer cylinder 63 is filled with a heating medium 62. Silica gel is generally used as the adsorbent 59, and ethylene glycol or alcohol group as the heating medium 62. Note that numeral 53a is an inlet of the heating medium 62 and 53b an outlet of the heating medium 62. The circulating blower 52, ozone generator 50 and adsorption/desorption tower 53 constitute, in this order, a single circulating system.
Operations will now be explained. There are two operations, namely an adsorbing operation and a desorbing operation of ozone.
The adsorbing operation will first be explained. Oxygen is supplied by the oxygen supply source 51 through an inlet 53c so that the pressure in the circulating system is always a constant pressure. At this time, the pressure is normally maintained at 1.5 kg/cm.sup.2. When oxygen is made to flow in the circulating system by the circulating blower 52 while the switch valves 57c and 57d are in an opened condition, a part of the oxygen is converted into ozone through silent discharge to generate ozonized oxygen while passing through the discharge space of the ozone generator 50, and the ozonized oxygen is then transferred to the adsorption/desorption tower 53. The adsorbent in the adsorption/desorption tower 53 selectively adsorbs ozone, and the remaining oxygen is returned to the circulating blower 52 through the switch valve 57c. Oxygen which has been consumed as ozone is supplemented through the oxygen supply source 51. At this time, the temperature of the ozone adsorbent is cooled by the cooling source 54 to not more than -30.degree. C. This is because the ozone adsorbing amount of the ozone adsorbent largely varies depending on the temperature. That is, by lowering the temperature, the ozone adsorbing amount increases and by raising the temperature, the ozone adsorbing amount decreases. Therefore, when adsorbing ozone, the adsorbent is cooled, and when desorbing ozone, the temperature of the adsorbent is raised.
When the adsorbent in the adsorption/desorption tower 53 has adsorbed ozone to approach the ozone saturation adsorption amount, the desorbing operation of ozone is performed. In the desorbing operation, operations of the ozone generator 50, the circulating blower 52 and cooling source 54 are terminated and the switch valves 57a to 57d are closed. Thereafter, the heating source 55 and water flow ejector 56 start their operations and switch valves 57e to 57g are opened. In order to enable easy desorption of ozone adsorbed at the adsorbent, heat of the heating medium 62 which has been injected from the heating source 55 through inlet 53a is applied from both the inner and outer surfaces of the inner cylinder 58 to raise temperature of the adsorbent 59. Then, by decompressing for sucking ozone in the adsorption/desorption tower 53 at one stroke to the outlet 53d through the water flow ejector 56, ozone is made to disperse and dissolve into water in the water flow ejector 56 which is then sent as ozone water to places where ozone is used. By decompression for suction, the achieved pressure in the adsorption/desorption tower 53 is made to be approximately 0.1 kg/cm.sup.2 (absolute pressure). When the desorbing period is completed in this way, the process returns to the initial adsorbing operation and is continuously repeated.
A conventional intermittent type ozone supplying apparatus is disadvantaged in that, by increasing the amount of filled silica gel for storing a large quantity of ozone, time required for cooling silica gel is increased so that ozone can not be efficiently stored, and it is also disadvantaged in that, by increasing the number of arranged ozone adsorption/desorption towers, the installation area is increased or the operation of the apparatus becomes complicated. Further, since the heating source and cooling source are separately arranged, the apparatus is made complicated and maintenance of silica gel in the adsorption/desorption towers is made difficult.
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an ozone supplying apparatus which is capable of shortening time required for cooling the ozone adsorbent, capable of efficiently storing ozone, and which can be arranged to be compact.